Consumerist is one of several sites Gawker has sold this year, including the political gossip blog Wonkette and the travel site Gridskipper. The blog offers consumer tips, like how to return products and how to confound a telemarketer, and covers shopper complaints, like excessive retail markups.

It will become part of a new division of Consumers Union, and the current editors will remain. No plans are under way to change the coverage or to begin charging for the site. “We don’t want to acquire the Consumerist and then squelch it in some way,” said Kevin McKean, vice president and editorial director of Consumers Union.

The founder and president of Gawker Media, Nick Denton, put Consumerist on sale in mid-November, the same day he announced that he was closing Valleywag, a site focused on technology in Silicon Valley.

In an interview on Tuesday, Mr. Denton said he was also in talks to sell Defamer, a show business gossip site, but he said he had no plans to sell other sites, which include the media sites Gawker and Jezebel.

Mr. Denton said the troublesome advertising market had led to the sale of Consumerist. In November, he posted a prediction that online advertising — which is how he supports his sites — would decline sharply next year. “I think people have generally been too optimistic” about online ads, he said Tuesday.

In buying Consumerist, Consumers Union is seeking to attract younger readers, with the hope of eventually selling them online or print subscriptions to Consumer Reports.

It is also something of a logical fit. Consumerist is popular, with about 1.8 million unique visitors a month, according to the online measurement service Quantcast, but has had trouble attracting advertising because the site often criticizes companies. Consumer Reports does not accept advertising, and once the sale closes on Jan. 1, neither will Consumerist.

Unlike most magazines, Consumer Reports makes its money from subscriptions, which cost $26 for the Web site or print edition. In the company’s last fiscal year, which ended May 31, it had $229 million in revenue — up 10.6 percent from the previous year — from Consumer Reports and a handful of smaller magazines.

In a year that has been difficult for magazines, Consumer Reports’ subscription and newsstand sales have risen. Circulation was 4.6 million, up from 4.3 million in 2007. The Web site has 3.3 million subscribers.

However, the average age of a print subscriber is 60, and the average ConsumerReports.org subscriber is 50. About 76 percent of Consumerist’s readers are 18 to 49, according to Quantcast.

Consumerist’s voice is younger, too: contributors write in the arch tone that is a hallmark of Gawker sites. But Consumers Union’s executive vice president, John Sateja, said that was not at odds with the more serious voice of Consumer Reports.

“When Consumers Union was formed, it was a pretty snarky, aggressive organization that took on big organizations just like Consumerist is doing today; it’s just going to an audience that we basically don’t reach,” Mr. Sateja said. “It may not be language, or voice or style that Consumers Union has, in recent years, become accustomed to, but it is part of the roots of the organization.”

The old-media and new-media worlds have clashed over not only editorial voice, but also editorial process. Most print magazines have strict fact-checking and sourcing policies, while blogs tend to be more lax.

Mr. McKean said Consumerist would function much as it had, but with support from Consumer Reports. “If they have something they’re doing where they say, ‘Gee, I’d really like to have a fact checker give this a second look,’ ” he said, “the fact checkers will jump right on it and do it.”

The editor of Consumerist, Ben Popken, will become co-executive editor of the site, sharing the title with its current senior editor, Meghann Marco. Mr. Popken said that two Consumerist contributors who had been laid off this year, Chris Walters and Carey Greenberg-Berger, would resume blogging in January.

Terms of the deal were not disclosed. The sale is expected to close on Thursday.

A version of this article appears in print on , on page B3 of the New York edition with the headline: Consumers Union to Buy Gawker Blog Consumerist. Order Reprints|Today's Paper|Subscribe